Commit 1b340d01 authored by Stanislav Kinsbursky's avatar Stanislav Kinsbursky Committed by Trond Myklebust
Browse files

NFS: DNS resolver cache per network namespace context introduced 



This patch implements DNS resolver cache creation and registration for each
alive network namespace context.
This was done by registering NFS per-net operations, responsible for DNS cache
allocation/register and unregister/destructioning instead of initialization and
destruction of static "nfs_dns_resolve" cache detail (this one was removed).
Pointer to network dns resolver cache is stored in new per-net "nfs_net"
structure.
This patch also changes nfs_dns_resolve_name() function prototype (and it's
calls) by adding network pointer parameter, which is used to get proper DNS
resolver cache pointer for do_cache_lookup_wait() call.

Note: empty nfs_dns_resolver_init() and nfs_dns_resolver_destroy() functions
will be used in next patch in the series.

Signed-off-by: default avatarStanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent 5c1cacb1

fs/nfs/dns_resolve.c

+63 −33
Original line number Diff line number Diff line
@@ -11,7 +11,7 @@ 
#include <linux/sunrpc/clnt.h>

#include <linux/dns_resolver.h>



ssize_t nfs_dns_resolve_name(char *name, size_t namelen,

ssize_t nfs_dns_resolve_name(struct net *net, char *name, size_t namelen,

		struct sockaddr *sa, size_t salen)

{

	ssize_t ret;
@@ -43,12 +43,11 @@ ssize_t nfs_dns_resolve_name(char *name, size_t namelen, 


#include "dns_resolve.h"

#include "cache_lib.h"

#include "netns.h"



#define NFS_DNS_HASHBITS 4

#define NFS_DNS_HASHTBL_SIZE (1 << NFS_DNS_HASHBITS)



static struct cache_head *nfs_dns_table[NFS_DNS_HASHTBL_SIZE];



struct nfs_dns_ent {

	struct cache_head h;
@@ -259,21 +258,6 @@ out: 
	return ret;

}



static struct cache_detail nfs_dns_resolve = {

	.owner = THIS_MODULE,

	.hash_size = NFS_DNS_HASHTBL_SIZE,

	.hash_table = nfs_dns_table,

	.name = "dns_resolve",

	.cache_put = nfs_dns_ent_put,

	.cache_upcall = nfs_dns_upcall,

	.cache_parse = nfs_dns_parse,

	.cache_show = nfs_dns_show,

	.match = nfs_dns_match,

	.init = nfs_dns_ent_init,

	.update = nfs_dns_ent_update,

	.alloc = nfs_dns_ent_alloc,

};



static int do_cache_lookup(struct cache_detail *cd,

		struct nfs_dns_ent *key,

		struct nfs_dns_ent **item,
@@ -336,8 +320,8 @@ out: 
	return ret;

}



ssize_t nfs_dns_resolve_name(char *name, size_t namelen,

		struct sockaddr *sa, size_t salen)

ssize_t nfs_dns_resolve_name(struct net *net, char *name,

		size_t namelen, struct sockaddr *sa, size_t salen)

{

	struct nfs_dns_ent key = {

		.hostname = name,
@@ -345,37 +329,83 @@ ssize_t nfs_dns_resolve_name(char *name, size_t namelen, 
	};

	struct nfs_dns_ent *item = NULL;

	ssize_t ret;

	struct nfs_net *nn = net_generic(net, nfs_net_id);



	ret = do_cache_lookup_wait(&nfs_dns_resolve, &key, &item);

	ret = do_cache_lookup_wait(nn->nfs_dns_resolve, &key, &item);

	if (ret == 0) {

		if (salen >= item->addrlen) {

			memcpy(sa, &item->addr, item->addrlen);

			ret = item->addrlen;

		} else

			ret = -EOVERFLOW;

		cache_put(&item->h, &nfs_dns_resolve);

		cache_put(&item->h, nn->nfs_dns_resolve);

	} else if (ret == -ENOENT)

		ret = -ESRCH;

	return ret;

}



int nfs_dns_resolver_init(void)

int nfs_dns_resolver_cache_init(struct net *net)

{

	int err;

	int err = -ENOMEM;

	struct nfs_net *nn = net_generic(net, nfs_net_id);

	struct cache_detail *cd;

	struct cache_head **tbl;



	cd = kzalloc(sizeof(struct cache_detail), GFP_KERNEL);

	if (cd == NULL)

		goto err_cd;



	tbl = kzalloc(NFS_DNS_HASHTBL_SIZE * sizeof(struct cache_head *),

			GFP_KERNEL);

	if (tbl == NULL)

		goto err_tbl;



	cd->owner = THIS_MODULE,

	cd->hash_size = NFS_DNS_HASHTBL_SIZE,

	cd->hash_table = tbl,

	cd->name = "dns_resolve",

	cd->cache_put = nfs_dns_ent_put,

	cd->cache_upcall = nfs_dns_upcall,

	cd->cache_parse = nfs_dns_parse,

	cd->cache_show = nfs_dns_show,

	cd->match = nfs_dns_match,

	cd->init = nfs_dns_ent_init,

	cd->update = nfs_dns_ent_update,

	cd->alloc = nfs_dns_ent_alloc,



	nfs_cache_init(cd);

	err = nfs_cache_register_net(net, cd);

	if (err)

		goto err_reg;

	nn->nfs_dns_resolve = cd;

	return 0;



	nfs_cache_init(&nfs_dns_resolve);

	err = nfs_cache_register_net(&init_net, &nfs_dns_resolve);

	if (err) {

		nfs_cache_destroy(&nfs_dns_resolve);

err_reg:

	nfs_cache_destroy(cd);

	kfree(cd->hash_table);

err_tbl:

	kfree(cd);

err_cd:

	return err;

}



void nfs_dns_resolver_cache_destroy(struct net *net)

{

	struct nfs_net *nn = net_generic(net, nfs_net_id);

	struct cache_detail *cd = nn->nfs_dns_resolve;



	nfs_cache_unregister_net(net, cd);

	nfs_cache_destroy(cd);

	kfree(cd->hash_table);

	kfree(cd);

}



int nfs_dns_resolver_init(void)

{

	return 0;

}



void nfs_dns_resolver_destroy(void)

{

	nfs_cache_unregister_net(&init_net, &nfs_dns_resolve);

	nfs_cache_destroy(&nfs_dns_resolve);

}



#endif

fs/nfs/dns_resolve.h

+12 −2
Original line number Diff line number Diff line
@@ -15,12 +15,22 @@ static inline int nfs_dns_resolver_init(void) 


static inline void nfs_dns_resolver_destroy(void)

{}



static inline int nfs_dns_resolver_cache_init(struct net *net)

{

	return 0;

}



static inline void nfs_dns_resolver_cache_destroy(struct net *net)

{}

#else

extern int nfs_dns_resolver_init(void);

extern void nfs_dns_resolver_destroy(void);

extern int nfs_dns_resolver_cache_init(struct net *net);

extern void nfs_dns_resolver_cache_destroy(struct net *net);

#endif



extern ssize_t nfs_dns_resolve_name(char *name, size_t namelen,

		struct sockaddr *sa, size_t salen);

extern ssize_t nfs_dns_resolve_name(struct net *net, char *name,

		size_t namelen,	struct sockaddr *sa, size_t salen);



#endif

fs/nfs/inode.c

+30 −3
Original line number Diff line number Diff line
@@ -51,6 +51,7 @@ 
#include "fscache.h"

#include "dns_resolve.h"

#include "pnfs.h"

#include "netns.h"



#define NFSDBG_FACILITY		NFSDBG_VFS
@@ -1552,6 +1553,25 @@ static void nfsiod_stop(void) 
	destroy_workqueue(wq);

}



int nfs_net_id;



static int nfs_net_init(struct net *net)

{

	return nfs_dns_resolver_cache_init(net);

}



static void nfs_net_exit(struct net *net)

{

	nfs_dns_resolver_cache_destroy(net);

}



static struct pernet_operations nfs_net_ops = {

	.init = nfs_net_init,

	.exit = nfs_net_exit,

	.id   = &nfs_net_id,

	.size = sizeof(struct nfs_net),

};



/*

 * Initialize NFS

 */
@@ -1561,9 +1581,13 @@ static int __init init_nfs_fs(void) 


	err = nfs_idmap_init();

	if (err < 0)

		goto out9;

		goto out10;



	err = nfs_dns_resolver_init();

	if (err < 0)

		goto out9;



	err = register_pernet_subsys(&nfs_net_ops);

	if (err < 0)

		goto out8;
@@ -1625,10 +1649,12 @@ out5: 
out6:

	nfs_fscache_unregister();

out7:

	nfs_dns_resolver_destroy();

	unregister_pernet_subsys(&nfs_net_ops);

out8:

	nfs_idmap_quit();

	nfs_dns_resolver_destroy();

out9:

	nfs_idmap_quit();

out10:

	return err;

}
@@ -1640,6 +1666,7 @@ static void __exit exit_nfs_fs(void) 
	nfs_destroy_inodecache();

	nfs_destroy_nfspagecache();

	nfs_fscache_unregister();

	unregister_pernet_subsys(&nfs_net_ops);

	nfs_dns_resolver_destroy();

	nfs_idmap_quit();

#ifdef CONFIG_PROC_FS

fs/nfs/netns.h

0 → 100644
+13 −0
Original line number Diff line number Diff line 
#ifndef __NFS_NETNS_H__

#define __NFS_NETNS_H__



#include <net/net_namespace.h>

#include <net/netns/generic.h>



struct nfs_net {

	struct cache_detail *nfs_dns_resolve;

};



extern int nfs_net_id;



#endif

fs/nfs/nfs4namespace.c

+5 −3
Original line number Diff line number Diff line
@@ -94,13 +94,14 @@ static int nfs4_validate_fspath(struct dentry *dentry, 
}



static size_t nfs_parse_server_name(char *string, size_t len,

		struct sockaddr *sa, size_t salen)

		struct sockaddr *sa, size_t salen, struct nfs_server *server)

{

	ssize_t ret;



	ret = rpc_pton(string, len, sa, salen);

	if (ret == 0) {

		ret = nfs_dns_resolve_name(string, len, sa, salen);

		ret = nfs_dns_resolve_name(server->client->cl_xprt->xprt_net,

					   string, len, sa, salen);

		if (ret < 0)

			ret = 0;

	}
@@ -137,7 +138,8 @@ static struct vfsmount *try_location(struct nfs_clone_mount *mountdata, 
			continue;



		mountdata->addrlen = nfs_parse_server_name(buf->data, buf->len,

				mountdata->addr, addr_bufsize);

				mountdata->addr, addr_bufsize,

				NFS_SB(mountdata->sb));

		if (mountdata->addrlen == 0)

			continue;

CRA Git | Maintained and supported by SUSTech CRA and CCSE